Optical apparatus for comparing objects



septfs, 1947.

K. BUTSCHER OPTICAL APPARATUS FOR COMPARING OBJECTS Filed Sept. l1, 1942v Patented Sept. 9, 1947 2,427,255 i C E OPTICAL APPARATUS FOR CONWARING OBJECTS Karl Butscher, Bienne, Switzerland, assignor to Maschinenfabrik H. Hauser A.G., Bienne, Switzerland, a joint-stock company of Switzerland Application September 11., 1942, Serial No. 457,988 In Switzerland July 16, 1940 Section 1, Public Law 690, August 8, 1946. Patent expires July 16, 1960 2 Claims.

'I'he object of the present invention is an optical apparatus for comparing objects.

If in a microscope with two objectives and a common eyepiece two objects, illuminated with white light, are examined, the individual images of these objects have the same colour (a greyishblack) with but slight contrast. If these individual images are superimposed, only those parts of the same are distinct, which' lie one upon the other. The mutual deviations of the objects, i. e. the non-superposed equally coloured parts of the images, specially if they are small, can hardly be distinguished and it is almost impossible to make out to which of the two objects to be compared the deviations belong. Thus it would be impossible to make controls in large numbers by which even th'e smallest deviations of the objects to be tested with regard to the pattern must be rapidly and exactly determined.

The apparatus according to the present invention remedies these inconveniences. This apparatus, specially but not exclusively a microscope is characterized by at least two originally separated paths of luminous beams passing through a common eyepiece, unequally coloured colour iilters being inserted into these paths.

Those parts of the images, which are made to lie one upon the other, appear to be black and the parts not lying one upon the other appear as coloured borders around the black image part. As the projecting parts of the one object always appear in one and those of the other object in another colour, the images of the deviations are not only very distinctly contrasted, but it at once becomes apparent to which object they belong.

Other objects and features will be apparent as the following description proceeds, reference being had to the accompanying drawing illustrating, as an example, one embodiment of the apparatus, in the form of a microscope, and in which Fig. 1 is a, diagrammatic illustration of the principle of the invention,

Figs. 2 to 5 show diagrammatically details of said principle,

Fig. 6 is a iront View of a microscope.

Fig. 7 is a side elevation of said microscope and Fig 8 a central section of an object carrier of the microscope.

In the following description the optical system may rst be explained.

In Fig. 1 th'e numerals I, 2 designate articial luminous sources, e. g., incandescent lamps.

These latter emit luminous beams 3, 4 which pass through colour lters 5, E, one of which, 5, may, e. g. be green, and the other, 6, red. Green rays are illustrated by ordinary dash and red rays by dash-double dot lines. Of course, other colours may be used, e. g. orange instead of red and blue in place of green. They must simply be colours distinctly contrasting from each other and from their mixed colour. After the lters the luminous beams, now green and red, pass through the aperture diaphragms 'I, 8. These latter lie in the focal planes of the illuminating lenses 9, I and produce a luminous beam which is at least approximately parallel. After the illuminating lenses 9, I0 the rays pass through the object planes II, I2 of the object carriers on which the opaque objects I3, I 4 to be compared lie (shown in Fig. 1 by a top View close to the dashes illustrating th'e objeci-l planes). Then the luminous beams go through the objectives I5, I6 and afterwards impinge on the reflecting surfaces I'I, I8 and I9, 20 respectively and are thus combined and the images of the objects are seen in the same eyepiece. The reecting surface I8 is semitransparent. In the same eyepiece eld a greenlighted image iield 2| with the image XIII of the object I3 now occurs and a red image ield 22 with the image XIV of the object I4. If only the luminous source I be switched on, a black image XIU of the object I3 is seen inthe green image iield 2|, or if only the source 2 is switched on, a black image XIV of the object I4 occurs in the red image field 22.

If both luminous sources are simultaneously switched on, an image field 23 with a mixed colour is obtained (Figs. 4 and 5). As red and green are so called complementary colours, the mixed colour is white in the case of White light (daylight) or light yellow to yellow if artificial (electric) light is used. Be it now supposed that th'e images XIII and XIV on the yellow mixed colourimage field 23 do not yet lie one upon the other (Fig. 4). If one considers, that, e. g. the object I3 does not transmit any light, its image XIlI, also on the mixed colour-image field 23, would be black if the red colour '22 of the other luminous beam were not superimposed (Fig. 2, the image is here considered as spatial and seen from the side.) Thus it happens that, in the mixed field 23, the image XIII (Fig. 4) of the object I3 lying in th'e green luminous beam appears red. Correspondingly, the image XIV of the object I4 lying in the red light appears to be green in the mixed image eld 23, since the green light 2l is superimposed on the black image (Fig. 3). Thus the colours of the individual images of the objects in the mixed colour-field are interchanged (Fig. 4). These two images now contrast Very distinctly in the mixed colour-held both from this latter and from each other.

If the two images shown in Fig. 4 are now superimposed, the superposed parts of these images appear black (Fig. 5), as the superimpositions 22 and 2i seen in Figs. 2 and 3 over the common image again give a neutral mixed colour, while pared are not exactly equal, the deviation of the' two objects from each other are obtained `as re'd and green borders R and G (Fig1'5) 5around the black common image partB'.V As tlfle'se borders contrast very distinctly both from the black common image part B and themixedcolour-image field 23 (yellow in case of electric light), `even` the slightest deviations can be made out exactly and rapidly, a fact very importantintheftesting l 44 passing through a slot 45 of the sleeve 4| and engaging a female thread 45 of the adjusting member 41. The tube 36 is vertically adjusted rotating this adjusting member 41 held between thel ange 48 of the sleeve 4| and the base plate 24. Ycolour Afil-ter 5, (6) mounted on said diaphragm,

The aperture diaphragm 1 (B), the

andthe illuminating lens 9 (Hl) are inserted into this tube3i," while the luminous source I (2) is located under the' tube in the interior of the base plate 24. The luminous sources are switched on faces l coinici/ridingV the'twolu'nious'fbeams, asngle objective 4rni'glit beprovided 'after thes`e`- reflecting surfaces. Should more than two' objects siniul-taneously be compared with one another," more than two luminousfbeams withrespect' e filters the pri'snihousing 3l; 'The'v structural arrange- Irl/exit ofthe objectives vand 4the reflecting surfaces to the housiffg and' ortho common eyepiece t2 is' carried out in a known" manner and, therefore, nee-d riot'b described. Of importance fis solely and off by means of the push button switches 49, 50. The xfilters may be placed anywhere in the pathof the luminous beams; owing to structural reasons`,' however, they are advantageously disposed close to the luminous source, i. e. in the tube of the object carrier.

For the comparative measurement of two objects the same are placedon'the plates 21, 23 ofthe object carriers and then the illuminating device is switched on. The images of these ob-` jects' are' now seen inthe eyepiece on'the mixed colour'irn'alge'eld in' two different colours. The images are focussed by rotating the adjusting memberV 41. Then the plates 21 and -28 are 'turned and the adjusting screwsSS, 39 moved until the' images coverL each: other as far as possible. Parts of the" objects devating` from one another are then to beseen as coloured borders on the black common image, whereby it may at once be recognized b'y the kindfoi colour which object hasparts projecting beyond the other objoot (Fig. 5).

what :como

l. 7In A'an optical apla'tus" for Vcnflpari'ng objects, an eyepiece, means for" forming two'originally 'separated paths of vluminous "beams,

means for combining said beam'sin saide'yfepiece, differently' colored `1"1' lters i'n` safid paths', vertically adjustabletubesin said paths', rot'atable and horizontally'shiftable-plalt-es mounted on said tubes having light transmittingportions aligned withsaiol tubes, andanilluminating lens in each oi Said tubes, said color lters being locatedin said tubes.' 2 man Optialf apparatus for ,Comparing @bjects, anfeylepiece, means for' for'milfig two` origithe fact that th'e column 33, carrying the'prism housing El,"and thev object carriers" 25', 25j are mounted on the base plate'in such a way that all theV operating screws of the. inicrosco'pe are easily accessible for manipulation. The 'column 33 is advantageously' disposed behind the object carriers.

'roo plato '21128) isrot'atobiy oolfiedon a.' twopart carrier34'. This later is4 s'lidably mounted on aiin'g 35 attached to thetube' 36. `Adjusting screws 38, 39 Aare"screwed into two bush`ingsi'31 mutual-ly displacedby acert'ain angle, e.' Ag. 9() .(inligl 8 only the n'of these bushingsV is t'ofbe seem.' Damot'rioaliy' opposite to these adjusting screws springs 4U'are inserted, acting" against the'adjusting'screws. These adjusting screws and springs n'abioth plato'to boiooved in two dir cotions, g". VI5erp'eiridic,ulafrly' to each other. 'I he tube 36`is, withallowance'ror verticaladjustment, inserted` in a'fsleve V4l'. This sleeve 4| provided with a'fshoulder 42 is' xed tothe base plate l24 by means of a screw nut 43j The:v following construction AenablesA 'theV tube to be verticallyY adjusted. Into the tube" 36is screwed' a guide pin nally separated paths of luminous beams, means 'for' combining said beams insaid eyepiece, rotatable and horizontally 'and vertically shiftabe object carriersinserted into'` said paths, each comprising averti'cally shiftable tubeand a rotatoble and horizontally shiftabl ptite mounted on said tube, having a light/transmitting portionaligned with said said tube, aperture diaphragm in said tube, and differently colored lters in said aperture diaphragins.

KARL BUTSCHER.

REFERENCES CiTED The following references are of record'in Ythe le of this patent:

` UNTLTED s'trA'iiEs' PATENTS Number Name Date 1,080,968 Hayes f. Dec. 9, 1913 1,161,848 Cornell et al. Nov. 30, 1915' 1,371,458 Wilson YMar. 15, 1921 

